Yes, so it changes a single die into a success. However, you could fail with both dice and turn one of those failures into a success - potentially saving your skin.
Viewing post in Rules clarification: default win.
I think, when you can even turn a double fail into one success, this can make models immortal as long as the Seer is near, which does not sound too balanced.
In this case would change of the rules text to
Change a single activation roll to a one
Solve this problem.
And the text as is implicates, that the model must be successfully activated, that's why I was a bit confused.